Emergency Airway Management in Patients with COVID-19: A Prospective International Multicenter Cohort Study.

BACKGROUND: Tracheal intubation for patients with COVID-19 is required for invasive mechanical ventilation. The authors sought to describe practice for emergency intubation, estimate success rates and complications, and determine variation in practice and outcomes between high-income and low- and middle-income countries. The authors hypothesized that successful emergency airway management in patients with COVID-19 is associated with geographical and procedural factors. METHODS: The authors performed a prospective observational cohort study between March 23, 2020, and October 24, 2020, which included 4,476 episodes of emergency tracheal intubation performed by 1,722 clinicians from 607 institutions across 32 countries in patients with suspected or confirmed COVID-19 requiring mechanical ventilation. The authors investigated associations between intubation and operator characteristics, and the primary outcome of first-attempt success. RESULTS: Successful first-attempt tracheal intubation was achieved in 4,017/4,476 (89.7%) episodes, while 23 of 4,476 (0.5%) episodes required four or more attempts. Ten emergency surgical airways were reported-an approximate incidence of 1 in 450 (10 of 4,476). Failed intubation (defined as emergency surgical airway, four or more attempts, or a supraglottic airway as the final device) occurred in approximately 1 of 120 episodes (36 of 4,476). Successful first attempt was more likely during rapid sequence induction versus non-rapid sequence induction (adjusted odds ratio, 1.89 [95% CI, 1.49 to 2.39]; P < 0.001), when operators used powered air-purifying respirators versus nonpowered respirators (adjusted odds ratio, 1.60 [95% CI, 1.16 to 2.20]; P = 0.006), and when performed by operators with more COVID-19 intubations recorded (adjusted odds ratio, 1.03 for each additional previous intubation [95% CI, 1.01 to 1.06]; P = 0.015). Intubations performed in low- or middle-income countries were less likely to be successful at first attempt than in high-income countries (adjusted odds ratio, 0.57 [95% CI, 0.41 to 0.79]; P = 0.001). CONCLUSIONS: The authors report rates of failed tracheal intubation and emergency surgical airway in patients with COVID-19 requiring emergency airway management, and identified factors associated with increased success. Risks of tracheal intubation failure and success should be considered when managing COVID-19.

A new formula based on height for determining endotracheal intubation depth in pediatrics: A prospective study.

STUDY OBJECTIVE: The main objective was to devise an endotracheal intubation formula based on pediatric patients' strongly correlated growth parameters. The secondary objective was to compare the accuracy of the new formula to the age-based formula from Advanced Pediatric Life Support Course (APLS formula) and the middle finger length-based formula (MFL-based formula). DESIGN: A prospective, observational study. SETTING: Operation. PATIENTS: 111 subjects age 4-12 years old undergoing elective surgeries with general orotracheal anesthesia. INTERVENTIONS AND MEASUREMENTS: Growth parameters, including age, gender, height, weight, BMI, middle finger length, nasal-tragus length, and sternum length, were measured before surgeries. Tracheal length and the optimal endotracheal intubation depth (D) were measured and calculated by Disposcope. Regression analysis were used to establish a new formula for predicting the intubation depth. A self-controlled paired design was used to compare the accuracy of the intubation depth between the new formula, APLS formula, and MFL-based formula. MAIN RESULTS: Height (R = 0.897, P < 0.001) was strongly correlated to tracheal length and the endotracheal intubation depth in pediatric patients. New formulae basing on height were established, including new formula 1: D (cm) = 4 + 0.1 × Height (cm) and new formula 2: D (cm) = 3 + 0.1 × Height (cm). Via Bland-Altman analysis, the mean differences for new formula 1, new formula 2, APLS formula and MFL-based formula were - 0.354 cm (95% LOA, -1.289 to 1.998 cm), 1.354 cm (95% LOA, -0.289 to 2.998 cm), 1.154 cm (95% LOA, -1.002 to 3.311 cm), -0.619 cm (95% LOA, -2.960 to 1.723 cm), respectively. The rate of optimal intubation for new formula 1 (84.69%) was higher than for new formula 2 (55.86%), APLS formula (61.26%), and MFL-based formula. (69.37%). CONCLUSIONS: The prediction accuracy for intubation depth of the new formula 1 was higher than the other formulae. The new formula based on height: D (cm) = 4 + 0.1 × Height (cm) was preferable to APLS formula and MFL-based formula with a high incidence of appropriate endotracheal tube position.

Preoperative shock index in major abdominal emergency surgery.

Introduction: Major abdominal emergency surgery (MAES) patients have a high risk of mortality and complications. The time-sensitive nature of MAES necessitates an easily calculable risk-scoring tool. Shock index (SI) is obtained by dividing heart rate (HR) by systolic blood pressure (SBP) and provides insight into a patient's haemodynamic status. We aimed to evaluate SI's usefulness in predicting postoperative mortality, acute kidney injury (AKI), requirements for intensive care unit (ICU) and high-dependency monitoring, and the ICU length of stay (LOS). Method: We retrospectively reviewed 212,089 MAES patients from January 2013 to December 2020. The cohort was propensity matched, and 3960 patients were included. The first HR and SBP recorded in the anaesthesia chart were used to calculate SI. Regression models were used to investigate the association between SI and outcomes. The relationship between SI and survival was explored with Kaplan-Meier curves. Results: There were significant associations between SI and mortality at 1 month (odds ratio [OR] 2.40 [1.67-3.39], P<0.001), 3 months (OR 2.13 [1.56-2.88], P<0.001), and at 2 years (OR 1.77 [1.38-2.25], P<0.001). Multivariate analysis revealed significant relationships between SI and mortality at 1 month (OR 3.51 [1.20-10.3], P=0.021) and at 3 months (OR 3.05 [1.07-8.54], P=0.034). Univariate and multivariate analysis also revealed significant relationships between SI and AKI (P<0.001), postoperative ICU admission (P<0.005) and ICU LOS (P<0.001). SI does not significantly affect 2-year mortality. Conclusion: SI is useful in predicting postopera-tive mortality at 1 month, 3 months, AKI, postoperative ICU admission and ICU LOS.

Bosentan affects 15-F2t-isoprostane adverse effects on postischemic rat hearts.

BACKGROUND: 15-F(2t)-isoprostane (IsoP), a marker of reactive oxygen species-induced oxidative stress, is increased after myocardial ischemia and reperfusion. It exerts deleterious effects on postischemic myocardium accompanied with increased release of endothelin-1 (ET-1), a potent vasoconstrictor. We hypothesized that IsoP exacerbates myocardial ischemia-reperfusion injury by stimulating ET-1 production, and that ET-1 blockade can attenuate or prevent these deleterious effects of IsoP. METHODS: Adult rat hearts were perfused by the Langendorff technique with Krebs-Henseleit solution (KH) at a constant flow rate of 10 mL/min. Global myocardial ischemia was induced by stopping KH perfusion for 40 min followed by 60 min of reperfusion. Hearts were randomized to one of the five groups (n = 8 each): untreated control, treated with IsoP (100 nM), or the ET-1 receptor A/B antagonist bosentan (1 µM) alone or in combination 10 min prior to, during 40 min global ischemia and 15 min of reperfusion, or treated with IsoP as above plus delayed administration of bosentan after 15 min of reperfusion. RESULTS: Coronary effluent ET-1 concentrations in the IsoP group were higher than those in the control group during ischemia and reperfusion (P < 0.05), which was associated with increased release of cardiac-specific creatine kinase, reduced cardiac contractility during reperfusion, and increased myocardial infarct size (all P < 0.05 versus control). Bosentan administration during early reperfusion exacerbated the IsoP deleterious effects, while delayed administration attenuated it. CONCLUSION: 15-F(2t)-isoprostane-induced ET-1 production during later reperfusion is detrimental to functional recovery of damaged myocardium, while ET-1 increase during early reperfusion seems to improve it.

Levels of miR-125a-5p are altered in Mycobacterium avium-infected macrophages and associate with the triggering of an autophagic response.

Macrophages are major pathogen-killing cells. Mycobacteria can represent a serious threat to human health, in particular Mycobacterium tuberculosis and, less so, the opportunistic Mycobacterium avium. They can cause disseminated infections because of their capacity to survive and proliferate within macrophage phagolysosomes. Accumulating evidence indicates that the regulation of miRNA expression is implicated in the mechanisms of defense of macrophages against mycobacterial infections. Nevertheless, the precise contribution of miRNAs is largely unknown. The present study analyzes the expression profile of miRNAs during M. avium infection of macrophages by means of microarrays. We detected that the levels of 23 miRNAs were significantly changed ≥2.5-fold 24 h after M. avium infection. In particular, MiR-125a-5p was found to be highly expressed as part of the known immunological response of macrophages to bacterial or viral infections. MiR-125a-5p overexpression inhibited the expression of target signal transducers and activators of transcription 3 (STAT3) in THP-1 cells. Conversely, inhibitors of miR-125a-5p had the opposite effect. Silencing of STAT3 significantly enhanced the level of autophagy in both uninfected and M. avium-infected cells. Overexpression of miR-125a-5p significantly increased autophagy and decreased M. avium survival within THP-1 cells. Instead, co-transfection with miR-125a-5p mimic and a human STAT3 expressing construct reversed the effects: autophagy decreased and intracellular bactericidal survival was improved. Taken together, our findings indicate that miR-125a-5p participates in the regulation of innate host defenses by targeting STAT3 and enhancing autophagy levels. The results reported here contribute to a better understanding of host defense mechanisms against mycobacterial infections and offer some clues about their control.

[Effects of esmolol and fentanyl on the hemodynamic and catecholamine response to tracheal intubation in hypertensive patients].

OBJECTIVE: To compare effects of esmolol and fentanyl on the hemodynamic and catecholamine response to tracheal intubation in hypertensive patients. METHODS: Sixty hypertensive patients were randomly allocated into one of four groups: the patients received 0.9% saline in group A, 2 mg/kg esmolol in group B, 2 microg/kg fentanyl in group C and 2 mg/kg esmolol combined with 2 microg/kg fentanyl in group D before intubation. Tracheal intubation was performed with 0.1 mg/kg midazolam, 0.6 mg/kg atracurium and 2 mg/kg propofol. Systolic arterial pressure (SAP), diastolic arterial pressure (DAP), heart rate (HR), rate-pressure product (RPP), plasma noradrenaline (NA) and adrenaline (A) concentrations were measured before and after intubation. RESULTS: SAP, DAP, HR, RPP, NA and A levels in group A at 1 and 3 minutes after intubation were significantly higher than the baseline values (all P<0.01). NA levels in group B and SAP in group C increased significantly after intubation (both P<0.05). The hemodynamics and catecholamine in group D after intubation were not significantly different from the baselines (all P>0.05). CONCLUSION: 2 mg/kg esmolol or 2 microg/kg fentanyl can partly reduce hemodynamic response to intubation and 2 mg/kg esmolol combined with 2 microg/kg fentanyl can completely attenuate the hemodynamic and catecholamine response in hypertensive patients.

[Effects of extracellular signal-regulated kinase inhibition by AG126 on tissue tumor necrosis factor-alpha expression and multiple organ dysfunction in rats with postburn Staphylococcus aureus sepsis].

OBJECTIVE: To investigate the effects of extracellular signal-regulated kinase (ERKs) inhibition by AG126 on tissue tumor necrosis factor-alpha (TNF-alpha) expression and multiple organ dysfunction in rats with postburn Staphylococcus aureus sepsis and its potential signal regulating mechanism. METHODS: To reproduce postburn sepsis model, male Wistar rats were inflicated with 20% total body surface area third-degree scald followed by Staphylococcus aureus challenge. 34 rats were randomly divided into four groups as follows: normal control group (n = 6), scald control group (n = 6), postburn sepsis group (n = 12), and AG126 treatment group (n = 10). Tissue samples from the liver, kidneys and lungs were collected to determine phosphorylated ERKs by Western blot analysis, and TNF-alpha mRNA expression as well as its protein levels. RESULTS: It was revealed that phosphorylated ERKs in the liver, lungs, and kidneys from postburn septic animals were up-regulated rapidly at 0.5 - 2.0 hours, being 1.94-fold (P < 0.05), 2.86-fold (P < 0.01), and 1.41-fold at 2.0 hours compared to normal controls, respectively. Treatment with AG126 could significantly reduce phosphorylated ERKs in lung tissue by 70.6% (P < 0.01) at 2.0 hours postburn sepsis, and almost completely inhibited ERKs activation in the liver and kidneys at various time points. Meanwhile, both TNF-alpha mRNA and protein expressions in the liver, lungs, and kidneys were significantly decreased in AG126-treated group following septic challenge (P < 0.05 or 0.01). In addition, 2.0 hours after Staphylococcus aureus infection, treatment with AG126 markedly improved hepatic and renal function parameters, including serum ALT, AST, Cr, as well as BUN levels (P < 0.05 or 0.01), together with significant decrease in pulmonary myeloperoxidase activity, compared to those without AG126 treatment. CONCLUSION: These data suggested that ERKs signal transduction might be involved in the pathogenesis of systemic inflammatory response and multiple organ dysfunction in postburn gram-positive bacterial sepsis. Early treatment with AG126 could significantly down-regulate TNF-alpha mRNA expression as well as protein levels in vital organs and attenuate multiple organ dysfunction induced by scald injury combined with Staphylococcus aureus challenge.

[Changes in Toll-like receptor 2 and 4 gene expression in vital organs in septic rats and their regulation mechanisms].

OBJECTIVE: To investigate the changes in Toll-like receptor (TLR) 2 and 4 gene expression in vital organs in septic rats and their potential regulation mechanism. METHODS: One hundred Wistar rats were randomly divided into normal controls (n=10), sham-operated group (n=10), septic group (n=60), and recombinant bactericidal/permeability increasing protein (BPI)-treated group (n=20). Severe sepsis was replicated by cecal ligation and puncture (CLP). Animals were sacrificed at different time points after CLP, tissue TLR2/4 mRNA expression in the liver, lungs, kidneys as well as intestine were measured by reverse transcription-polymerase chain reaction (RT-PCR). Plasma levels of tumor necrosis factor-alpha(TNF-alpha) and interleukin-10 (IL-10) were also determined by enzyme linked immunoadsorbent assay (ELISA). RESULTS: TLR2/4 mRNA could be detected in various tissues with low values both in normal controls and sham-operated group, but they were markedly up-regulated at 2 hours after CLP, peaking at 6-12 hours. Tissue TLR4 mRNA was gradually down-regulated 24 hours later, while TLR2 mRNA levels maintained high values up to 72 hours. In comparison with the CLP group, treatment with BPI significantly decreased TLR2 mRNA in various tissues at 12 and 24 hours (P<0.05 or P<0.01), also tissue TLR4 mRNA at 12 hours (P<0.05 or P<0.01), without marked influence on TLR4 mRNA expression at 24 hours in liver, lungs and small intestine (P>0.05). In addition, treatment with BPI could significantly lower plasma TNF-alpha levels at 12 hours post-CLP, on the other hand markedly elevate plasma IL -10 levels 24 hours later (P<0.01). CONCLUSION: These data suggest that severe peritoneal infection could result in up-regulation of TLR2/4 mRNA expression in vital organs, which might play important roles in mediating proinflammatory cytokine synthesis and release. Endotoxemia appears to be involved in the activation of tissue TLR2/4 expression associated with CLP-induced sepsis.

[Effect of tryptase inhibitors on histamine release from human colon mast cells].

AIM: To investigate the effect of tryptase inhibitors (TPIs) on histamine release from human colon mast cells. METHODS: Human mast cells were prepared by digestion of colon tissue and with collagenase and hyaluronidase, cultured with four kinds of TPIs, leupeptin, protamine, TLCK, and lactoferrin for 15 min at 37 degrees Celsius respectively. A glass fibre-based fluorometry assay was used to detect histamine in mast cell suspension. RESULTS: 200 mmol/L leupeptin and 100 mmol/L protamine were able to stimulate histamine release from colon mast cells, while TLCK and lactoferrin did not. All TPIs inhibited anti-IgE-induced histamine release in a concentration dependent manner, and the inhibitory rates were 48.7%, 36.7%, 40.2% and 34.1%, respectively. However preincubation of TPIs with mast cells for 20 min at 37 degrees Celsius before adding anti-IgE had little effect on anti-IgE induced histamine release. All TPIs were able to inhibit calcium ionophore (CI)-induced histamine release, and the maximum inhibition rate was between 25%-32%. Inhibition on histamine release by leupeptin and TLCK obviously enhanced when colon mast cells were preincubated with them for 20 min before adding CI. However, under the same condition, protamine failed to inhibit histamine release. CONCLUSION: We prove for the first time that TPIs inhibit anti-IgE-and CI-induced histamine release from human colon mast cells, suggesting that it is possible to treat inflammatory bowel disease or other mast cell-related diseases by using TPIs.